This invention relates to an improvement in grain drying methods.
Grains and corn in particular, that is either too wet or too dry, does not have the sales value or feed value of corn that has a correct and desired moisture content. Thus, corn which is too wet will represent a direct financial loss to the farmer. In addition, corn which is too wet is subject to more spoilage and the potential for mold growth than is dryer corn.
Corn as it is harvested typically will have a moisture content from 20% to 25%. As explained earlier, this corn must be dried, typically to a moisture within the range of 13% to about 17% by weight prior to sale. If the farmer fails to dry the corn he will be docked in the price at the time of the sale. As a result of both the financial factor of selling high moisture grain as well as the spoilage factor, most grain producers dry the grain prior to storage or sale. In a typical drying operation, that is bin-drying, the bin is first loaded with the high moisture grain and thereafter heated air is supplied to the interior of the bin through a ventilated floor and flows upward through the grain. In some instances, and for the purpose of facilitating the flow of air through the grain, a perforated tube at the center of the bin is extended upwardly through the grain. In addition, the sidewalls of the bin may be of a perforated construction. Finally, in order to maximize the drying efficiency of the heated air which is moved upwardly through the bin (the air typically is heated by a liquid propane burner), the grain is oftentimes circulated through the bins by use of grain circulating augers. The value of the grain circulating system is that it prevents hot air scorching of the grain most near the heaters, and it allows the grain more remotely spaced from the heaters to be effectively subjected to hot air. As a result, a more uniform moisture content dried grain is obtained. For typical examples of bin drying stored grain, see Shivvers, U.S. Pat. Nos. 3,563,399, 3,765,547, and 3,765,548.
An improvement on the bin grain drying system includes circulating the grain through the drying bin and thereafter transferring the grain via an outlet at the top of the bin to grain storage bins, referred to herein as holding bins. This invention relates to an improvement in the "double bin" drying system. The term "double bin" drying system as used herein, is intended to mean where a first bin is employed with heaters for heating and drying a grain such as corn, and the corn product which has achieved the desired moisture content is thereafter removed and conveyed to a holding bin for storage.
As a result of the employment of the grain drying system of the present invention, fuel costs can be substantially reduced, as much as 40% to 50%, and the problems of clogging forced air fans with "bee's wings" or in other words, corn chaff, are obivated.
The method of accomplishing the advantages of this invention i.e., substantially decreased fuel costs for grain drying and elimination of problems associated with corn chaff clogging forced air fans, are obviated by the method of this invention.
Heretofore, the particularly in grain drying systems which involve circulation of the grain within a drying bin, only limited success has been achieved with recirculation of hot air within the grain drying bin in order to more effectively and efficiently utilize the hot air from the propane burners. The reason for such limited success is that as the grain is continually moved within the drying bin, corn chaff is disengaged from the kernel. This corn chaff, commonly referred to as "bee's wings", is segregated from the kernels because of its light weight and is drawn with a forced air recircultion fan back to the burner along with recycle hot air. As a result, such bee's wings often accumulated in piles and either clog the forced air fan or if exposed to the flames of the burner, will burn and cause fires. As a result, complex filter systems had to be utilized, or hot air recirculation had to be abandoned.
In the grain drying system of the present invention, the problem of bee's wings interfering with hot air recirculation has been obviated since the hot corn itself in a holding bin, after transfer from the drying bin, acts as a filter to effectively prevent bee's wings transfer back to the grain drying bin along with recycled hot air.
The manner of achieving the advantages of the invention, as well as other objects of the invention will be discussed hereinafter, will become apparent from the detailed description of the invention which follows.